JPH11199644A - Production of flexible polyurethane foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a flexible polyurethane foam by using a catalyst having an extremely high retardation effect and extremely low corrosivity. SOLUTION: This method for producing a flexible polyurethane foam by reacting a polyol with a polyisocyanate in the presence of a catalyst and a foaming agent. Therein, the catalyst comprises one or more kinds of compounds selected from quaternary ammonium carbonates expressed by the formula [R1 to R8 are each a 1-12C linear or branched saturated or unsaturated hydrocarbon group; (n) is 0-3, wherein, when (n) is 0, either of R1 to R3 and R5 or R6 may arbitrarily be bound to each other to form a heterogeneous ring, and wherein, when (n) is 1-3, R5 or R6 and R4 may be bound to each other to form a heterogeneous ring].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a flexible polyurethane foam by reacting a polyol and a polyisocyanate in the presence of a catalyst, a foaming agent and a foam stabilizer. More specifically, the present invention relates to a method for producing a flexible polyurethane foam, which comprises using a quaternary ammonium carbonate having a high polyurethane reaction activity and a low odor, a retardation property and a low corrosion property.

[0002]

2. Description of the Related Art Flexible polyurethane foams are widely used in furniture, automobile interior materials, bedding, cushions and other products because of their light weight and excellent elasticity. In recent years, regarding the production of these polyurethane products, productivity improvement, moldability improvement,
There are calls for improvements in physical properties and response to environmental issues. For this reason, highly active and highly functional catalysts have been demanded.

For example, in order to improve the productivity and the moldability, a catalyst having a retarding effect is required. As a physical property improvement, a catalyst effective in improving the air permeability, and in order to cope with the environment, a catalyst having less odor is required. There is a strong demand for the development of amine catalysts and catalysts suitable for formulations that reduce foaming agents and CFCs.

In the production of polyurethane foam, it is known that the organic carboxylate of a tertiary amine compound described in JP-A-60-58418 is a useful retarding catalyst. Since this lagging catalyst has a low initial activity, the time from mixing of the raw material polyol and the organic isocyanate to the start of the foam formation reaction can be extended. As a result, the operability and liquid flowability of the mixed liquid can be improved, for example, the raw material liquid can sufficiently flow to every corner of the large mold. Further, in this catalyst, when the foam formation reaction proceeds and the reaction temperature rises, the tertiary amine compound is thermally dissociated, and the catalytic activity is exhibited. As a result, the catalytic activity is significantly increased, and the foam formed by the foaming reaction can be flowed into the complicated mold without underfilling. Furthermore, since the curing speed of the foam is shortened, the demolding time of the foam is shortened, which helps to significantly improve productivity.

[0005]

However, the catalysts for polyurethane production which have been used so far as having a retarding effect have various problems. For example, the third
Since the organic carboxylate of a lower amine compound has a low pH,
Has strong corrosive properties. Therefore, there is a problem that the material of the urethane foaming machine or the like is easily corroded, and the productivity is lowered.

To solve the above problem, it is possible to increase the pH by reducing the amount of the organic carboxylic acid, but there is a problem that it is difficult to achieve the desired retardation.

Although there is a method for solving the above problem by mixing an appropriate tertiary amine compound with an organic carboxylate of a tertiary amine compound, the use of an organic carboxylic acid is essential. Therefore, the problem of corrosion could not be completely solved.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for producing a flexible polyurethane foam using a catalyst having an extremely high retarding effect and an extremely low corrosiveness. It is.

[0009]

Means for Solving the Problems The present inventors have made intensive studies from the viewpoint of a catalyst in a process for producing a flexible polyurethane foam. As a result, they have found that a quaternary ammonium salt-based catalyst having a special structure has an extremely high retarding effect in the production of a flexible polyurethane foam and has extremely low corrosiveness, and has completed the present invention.

That is, the present invention provides a method for producing a flexible polyurethane foam by reacting a polyol and a polyisocyanate in the presence of a catalyst and a foaming agent.

[0011]

Embedded image

(Wherein, R1 to R8 are linear or branched saturated or unsaturated hydrocarbon groups having 1 to 12 carbon atoms, and n = 0
~ 3. However, when n = 0, any one of R1 to R3 and R5 or R6 may be arbitrarily bonded to form a hetero ring. When n = 1 to 3, R5 or R6 and R
4 may combine to form a hetero ring. The method for producing a flexible polyurethane foam is characterized by using one or more selected from quaternary ammonium carbonates represented by the formula (1).

Hereinafter, the present invention will be described in detail.

The catalyst used in the production method of the present invention is one or more selected from quaternary ammonium carbonates represented by the above general formula (1). The method for producing the quaternary ammonium carbonate is not particularly limited. For example, the quaternary ammonium carbonate is formed by reacting a corresponding tertiary amine with a carbonic acid diester (such as dimethyl carbonate). Obtainable.

As the corresponding tertiary amine, for example,
The following are mentioned. That is, N, N, N ',
N'-tetramethylethylenediamine, N, N, N ',
N'-tetramethylpropylenediamine, N, N,
N ', N ", N" -pentamethyldiethylenetriamine, N, N, N', N ", N" -pentamethyl- (3-
Aminopropyl) ethylenediamine, N, N, N ',
N ", N" -pentamethyldipropylenetriamine,
N, N, N ', N'-tetramethylguanidine, 1,
3,5-tris (N, N-dimethylaminopropyl) hexahydro-S-triazine, 1,8-diazabicyclo [5.4.0] undecene-7, triethylenediamine, N, N, N ', N'-tetra Methylhexamethylenediamine, N-methyl-N '-(2-dimethylaminoethyl) piperazine, N, N'-dimethylpiperazine, N
-Methylmorpholine, N-ethylmorpholine, bis (2
-Dimethylaminoethyl) ether, 1-methylimidazole, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, 1-dimethylaminopropylimidazole and the like tertiary amine compounds. Of these, particularly preferred are N, N, N ',
N'-tetramethylethylenediamine, N, N, N ',
N ", N" -pentamethyldiethylenetriamine, triethylenediamine, and N, N, N ', N'-tetramethylhexamethylenediamine.

When these catalysts are used in the production method of the present invention, they exhibit excellent retarding effects, low corrosiveness and low odor. Usually, the amount is 0.01 to 10 parts, preferably 100 parts by weight, based on 100 parts of polyol used.
5 to 5 parts.

In the production method of the present invention, a catalyst other than the quaternary ammonium carbonate represented by the above general formula (1) can be used in combination as a catalyst. Examples of other catalysts include conventionally known tertiary amines and organic acid salts of tertiary amines.

The tertiary amine other than the quaternary ammonium carbonate represented by the general formula (1) is not particularly limited as long as it is conventionally known.
For example, N, N, N ', N'-tetramethylethylenediamine, N, N, N', N'-tetramethylpropylenediamine, N, N, N ', N ", N" -pentamethyldiethylenetriamine, N, N ', N ", N" -pentamethyl- (3-aminopropyl) ethylenediamine;
N, N, N ', N ", N" -pentamethyldipropylenetriamine, N, N, N', N'-tetramethylguanidine, 1,3,5-tris (N, N-dimethylaminopropyl) hexahydro -S-triazine, 1,8-diazabicyclo [5.4.0] undecene-7, triethylenediamine, N, N, N ', N'-tetramethylhexamethylenediamine, N-methyl-N'-(2- Dimethylaminoethyl) piperazine, N, N'-dimethylpiperazine, N-methylmorpholine, N-ethylmorpholine,
Bis (2-dimethylaminoethyl) ether, 1-methylimidazole, 1,2-dimethylimidazole, 1-
Tertiary amine compounds such as isobutyl-2-methylimidazole and 1-dimethylaminopropylimidazole are exemplified. Of these, particularly preferred is triethylenediamine. The use ratio is preferably in the range of 0.1 to 2.0 parts by weight of triethylenediamine to 1.0 part by weight of the quaternary ammonium carbonate. When the use ratio of triethylenediamine is 0.1 part by weight or less, the formation of the foam may be incomplete, and may cause shrinkage or depression. On the other hand, the use ratio of triethylenediamine is 2.0
If the amount is more than the weight part, the expected delay effect may not be exhibited.

In the production method of the present invention, a quaternary ammonium carbonate and an organometallic catalyst may be used in combination as a catalyst. As an organic metal catalyst, stannas diacetate,
Stanas dioctoate, Stanas dioleate, Stanas dilaurate, Dibutyltin oxide, Dibutyltin diacetate, Dibutyltin dilaurate, Dibutyltin dichloride, Dioctyltin dilaurate, Lead octanoate, Lead naphthenate, Nickel naphthenate, Cobalt naphthenate And the like. Among these, preferred compounds are organotin catalysts, and more preferred are stannas dioctoate and dibutyltin dilaurate. When using an organometallic catalyst in the present invention, the amount used is:
When the polyol is 100 parts by weight, usually 0.01 to
5.0 parts by weight, and more preferably 0.05 to 3.0 parts by weight.
Parts by weight. For example, when the amount of the organometallic catalyst used is 0.
If the amount is less than 05 parts by weight, the foam tends to crack, and if it is more than 3.0 parts by weight, the foam may shrink.

As the polyol used in the production method of the present invention, conventionally known polyether polyols, polyester polyols, polymer polyols and the like can be used. More preferred are polyether polyols and polymer polyols or mixtures thereof.

Examples of the polyether polyol include polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane, and pentaerythritol; amines such as ethylenediamine; alkanolamines such as ethanolamine and diethanolamine. A compound having at least two or more active hydrogen groups is used as a starting material, and an addition reaction of the compound with an alkylene oxide represented by ethylene oxide or propylene oxide, for example, Polyurethane
Handbook (by Gunter Oertel)
Those manufactured by the method described on pages 42 to 53 are exemplified. Particularly preferred is a polyether polyol having a molecular weight of about 3,000 to 12,000 using glycerin as a starting material.

As the polymer polyol, for example, the polyol is reacted with an ethylenically unsaturated monomer such as butadiene, acrylonitrile, styrene and the like in the presence of a radical polymerization catalyst.
ane Handbook (Gunter Oerte
l) Polymer polyols described on pages 75 to 76. Particularly preferred polymer polyols are those having a molecular weight of about 5,000 to 12,000.

The mixing ratio between the polyether polyol and the polymer polyol is preferably in the range of 50:50 to 90:10.

The polyisocyanate used in the present invention may be any known organic polyisocyanate, and is not particularly limited. Examples thereof include toluene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), Naphthylene diisocyanate,
Aromatic polyisocyanate such as xylylene diisocyanate, aliphatic polyisocyanate such as hexamethylene diisocyanate, dicyclohexyl diisocyanate,
Cycloaliphatic polyisocyanates such as isophorone diisocyanate and mixtures thereof. As TDI and its derivatives, a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate or TD
The terminal isocyanate prepolymer derivative of I can be mentioned. Examples of MDI and its derivatives include a mixture of MDI and its polymer, polyphenyl-polymethylene diisocyanate, and / or a diphenylmethane diisocyanate derivative having a terminal isocyanate group. Particularly preferred in the production method of the present invention is a mixture of TDI and MDI.

In the present invention, although the isocyanate index is not particularly limited, it is generally from 70 to 70.
The range is 130.

As the foaming agent used in the present invention, water and / or a halogenated hydrocarbon can be used. As the halogenated hydrocarbon, known halogenated methanes and halogenated ethanes, for example, methylene chloride, trichlorofluoromethane, dichlorodifluoromethane, dichlorotrifluoromethane, dichloromonofluoromethane and the like can be used. A particularly preferred blowing agent is water, and the amount used may vary depending on the density of the intended foam, but is usually 2 parts by weight or more, more preferably 3.0 to 8.0 parts by weight, per 100 parts by weight of the polyol. Parts by weight.

The foam stabilizer used in the present invention is a conventionally known organic silicon surfactant, and its amount is 0.1 to 10 parts by weight based on 100 parts by weight of the polyol.

In the present invention, if necessary, a crosslinking agent or a chain extender can be added. Examples of the crosslinking agent or chain extender include ethylene glycol, 1,4-butanediol, low molecular weight polyhydric alcohols such as glycerin, diethanolamine, low molecular weight amine polyols such as triethanolamine, or ethylenediamine.
Examples thereof include polyamines such as xylylenediamine and methylenebisorthochloroaniline. Of these, diethanolamine and triethanolamine are preferred.

In the present invention, a coloring agent, a flame retardant, an antioxidant and other known additives can be used as required. The types and amounts of these additives can be used in a range usually used as long as they do not deviate from known types and procedures.

[0030]

Industrial Applicability The quaternary ammonium carbonate used as a catalyst in the present invention has a low activity because of its high activity, is effective in reducing the production cost of polyurethane, and has a low initial activity. And the time from when the organic isocyanate is mixed until the foam formation reaction is started can be extended. As a result, it is possible to improve the operability of the mixed liquid, the liquid flowability, and the like, such that the raw material liquid can sufficiently flow to every corner of the large mold.

The quaternary ammonium carbonate used as a catalyst in the present invention develops its catalytic activity as the foam formation reaction proceeds and the reaction temperature rises.
As a result, the catalytic activity is significantly increased, allowing the foam formed by the foaming reaction to flow into the complex mold without underfilling. Further, since the curing speed of the foam is shortened, the demolding time of the foam is shortened, which contributes to a significant improvement in productivity.

Further, the foam obtained by the production method of the present invention has characteristics of low density and excellent air permeability.

The quaternary ammonium carbonate used as a catalyst in the present invention has an extremely low odor, significantly improves the working environment in the foam production process, and gives a bad odor to the flexible polyurethane foam obtained by the production method of the present invention. Is not left.

Further, since the quaternary ammonium carbonate used as a catalyst in the present invention has extremely low corrosiveness to metal materials, the quaternary ammonium carbonate does not harm the polyurethane production equipment such as a catalyst storage tank and a foaming device, and can improve productivity. Useful.

[0035]

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

<Production of Catalyst> Production Example 1 N, N, N ', N ", N" -pentamethyldiethylenetriamine (1 mol), dimethyl carbonate (1.5 mol) and methanol (2 mol) as a solvent were placed in a stirred autoclave. .0
Mol) and reacted at a reaction temperature of 110 ° C. for 12 hours to obtain a methanol solution of the product. The desired product was obtained by removing unreacted dimethyl carbonate and methanol by distillation. The properties are 13C-NMR and 1H-
NMR revealed that the main component was bis (N- (3,6,6-trimethyl-3,6-diazaheptyl) -N, N, N-trimethylammonium) carbonate.
Hereinafter, this is referred to as catalyst A.

Production Example 2 In place of N, N, N ', N ", N" -pentamethyldiethylenetriamine (1 mol) in Production Example 1, N,
A main component is bis (N, N-dimethylaminoethyl-N'-trimethylammonium) carbonate in the same manner as in Production Example 1 except that N, N ', N'-tetramethylethylenediamine (1 mol) was used. Was obtained. Hereinafter, this is referred to as catalyst B.

Production Example 3 The same as Production Example 1 except that N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine (1 mol) was replaced by triethylenediamine (1 mol). The main component is bis (1-methyl-1-azonia-
8-azabicyclo [2,2,2] octane) .carbonate was obtained. Hereinafter, this is referred to as catalyst C.

Production Example 4 N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine (1 mol) in Production Example 1 was replaced with N,
The main component was bis (N, N-dimethylaminohexamethylene-N) in the same manner as in Production Example 1 except that N, N ', N'-tetramethylhexamethylenediamine (1 mol) was used.
'-Trimethylammonium) .carbonate was obtained. Hereinafter, this is referred to as catalyst D.

<Manufacture of Flexible Polyurethane Foam Products> Examples 1 to 4 By the combination of polyol and polyisocyanate shown in Table 1 (isocyanate index = 105), quaternary ammonium salt-based catalysts were used in Production Examples 1 to 3. Using the produced catalysts A, B, C and D, a flexible polyurethane foam was prepared using a foaming agent and a foam stabilizer as shown in Table 1.
Reactivity of flexible polyurethane foam (cream time,
Gel time, rise time), delay effect (L as catalyst
Based on the case where No. 33 was used, the number of seconds in which the cream time was prolonged by the use of each catalyst) and the physical properties (density and air permeability) of the molded foam were measured and evaluated. The evaluation results are shown in Table 1.

[0041]

[Table 1]

Table 1 shows that the quaternary ammonium salt catalyst used in the present invention can delay the initial reaction (cream time). Furthermore, the catalyst causes little corrosion of the metal material. Further, a foam having a low density and a high air permeability can be manufactured. Furthermore, it has low odor, improves the working environment in the foam manufacturing process, and does not leave odor in the final foam product.

Comparative Examples 1 and 2 In accordance with the formulation shown in Table 1, the same adjustments as in Example 1 were performed except that a conventional catalyst was used. The evaluation results are shown in Table 1.

When the conventional tertiary amine catalyst shown in Comparative Example 1 was used, the cream time was not extended if the gel time was the same.

When the conventional organic carboxylate of a tertiary amine compound shown in Comparative Example 2 is used, the cream time is delayed, but the catalytic activity is low, and it is necessary to use a large amount of the catalyst. . Further, corrosion of the metal material is significantly caused by the influence of the organic carboxylic acid contained in the catalyst.

Claims (2)

[Claims] 1. A polyol and a polyisocyanate,
In a method for producing a flexible polyurethane foam by reacting in the presence of a catalyst and a blowing agent, a catalyst represented by the following general formula (1): (Wherein, R1 to R8 are linear or branched saturated or unsaturated hydrocarbon groups having 1 to 12 carbon atoms, and n = 0 to 3).
However, when n = 0, any one of R1 to R3 and R5 or R6 may be arbitrarily bonded to form a hetero ring.
When n = 1 to 3, R5 or R6 and R4 may combine to form a hetero ring. A process for producing a flexible polyurethane foam, comprising using one or more selected from quaternary ammonium carbonates represented by the formula (1). 2. Polyol and polyisocyanate,
A method for producing a flexible polyurethane foam by reacting in the presence of a catalyst and a blowing agent, wherein the catalyst is used as a catalyst.
A method for producing a flexible polyurethane foam, comprising using a quaternary ammonium carbonate described in 1 above and triethylenediamine in combination.